The care of critically ill patients is increasingly complex and clinicians frequently suffer from information and generate a systematic and reasonable therapy plan. Computerized decision support systems can assist the clinician with many of the task such as the interactive management of mechanical ventilation. This decision support not only standardizes care but may improved the quality of care by reducing mistakes. This standardization of care also makes it possible to thoroughly characterize the current treatment process in order to compare it to a proposed new therapy as part of an ongoing continuous quality improvement (CQI) program. A computerized decision support system for the management of mechanical ventilation (respirator evaluation, oxygenation, ventilation, weaning an extubation) in patients with adult respiratory distress syndrome (ARDS) has already been developed and clinically validated at the LDS Hospital. The computerized decision support system was used for over 35,000 hours in 111 ARDS patients and has controlled decision making 95% of the 24 hour day. The survival rate was 67%, higher than the expected 31-33% from historical data, p<0.05. These results have demonstrated that computerized decision support for critical care is feasible. Our long term goal is to develop and test the efficacy of a computerized decision support system (protocols) for the standardized management of critically ill patients. This proposal will answer 2 questions: 1) Can a computerized decision support system be exported to other centers and used by clinicians uninvolved with its development? and 2) Does the system have an impact on patient outcome? During year 1, the knowledge base (protocol logic rules) were transferred from the HELP system at LDS Hospital to a PC based ICU computer system known as ARGUS Windows. The ARGUS Windows system has been installed at all 12 beds of the surgical ICU at King Drew Medical Center (KDMC) in Los Angeles, CA. This system is now in routine use for respiratory care charting and the decision support system has been used to successfully care for 5 ARDS patient in a pilot study of feasibility. We propose to conduct a prospective randomized clinical trial to test efficacy of computerized protocols in 400 patients with ARDS at two different clinical sites; KDMC a county hospital in the Watts district of Los Angeles, CA and Hermann Hospital, a private hospital in Houston affiliated with University of Texas Medical School (HO: There is no difference in efficacy between protocol and non- protocol controlled critical care). We will define efficacy using a hierarchical four level approach; Efficacy a) Survival, b) Length of ICU Stay, c) Morbidity, d) Incidence and severity of barotrauma. Generalizability of the computerized decision support system will be determined by examining; 1) Percent of total time in the trial during which protocols controlled patients care. 2) Number of protocol instructions which were not allowed. 3) Number of objections to protocol logic which, based on medical evidence, forced a change in the logic. Three patients have already been randomized into this study at KDMC (2 controls and 1 protocol controlled care).